1. Field of the Invention
The present invention relates to a hacksaw, and more particularly to a hacksaw including an easily operated blade tension device.
2. Description of the Prior Art
Various kinds of typical hacksaws have been developed and comprise various kinds of blade tension devices for tensioning the saw blades. U.S. Pat. No. 3,822,731 to Keymer, U.S. Pat. No. 4,466,471 to Thomson, U.S. Pat. No. 5,826,344 to Phelon et al., and U.S. Pat. No. 6,134,791 to Huang disclose four of the typical hacksaws, and comprise a rotatable lever for tensioning the saw blade, and a latch for locking the lever.
However, the typical hacksaws comprise a complicated configuration that may not be easily assembled. In addition, most of the latches or the knobs include a tiny volume or area that may not be easily operated by the users.
In addition, some of the latches or knobs of the typical hacksaws may be actuated inadvertently while working, such that the saw blades may have a good chance to be loosened inadvertently while working.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional hacksaws.
The primary objective of the present invention is to provide a hacksaw including an easily operated blade tension device,
In accordance with one aspect of the invention, there is provided a hacksaw comprising a frame including a beam having a front portion and a rear portion, a leg and a handle extended downward from the front portion and the rear portion of the beam respectively, the handle including an upper portion and a lower portion and including a chamber formed therein, an arm including a front portion pivotally secured to the lower portion of the handle, and including a rear portion having an oblong hole formed therein, a saw blade detachably coupled between the leg and the front portion of the arm, a lever including an upper portion pivotally secured to the upper portion of the handle with a pivot shaft, and including a lower portion, and including an upper and front portion, a tension rod including an upper portion pivotally secured to the upper and front portion of the lever with a pivot pole, and including a lower portion extended through the oblong hole of the arm and engageable with the rear portion of the arm, the tension rod being movable up and down relative to the handle by rotating the lever inward and outward of the chamber of the handle about the pivot shaft, a latch including a block slidably received in the chamber of the handle, and having an orifice formed therein for slidably receiving the tension rod, and means for biasing the latch to engage with the lever and to retain the lever in the chamber of the handle.
The biasing means includes a spring engaged between the block and the rear portion of the arm.
A stop may further be provided and attached onto the tension rod and engageable with the block of the latch, for limiting the block of the latch to move relative to the tension rod.
The handle includes a pair of plates for defining the chamber thereof between the plates, and means for guiding the latch to move relative to the handle.
The guiding means includes at least one rail provided on the plates, and at least one channel formed in the block for slidably receiving the at least one rail.
The lower portion of the lever includes a lock notch formed therein, the latch includes an upper portion having a catch provided thereon for engaging with the lock notch of the lever.
The lower portion of the lever may also include a lock tongue provided thereon, the latch includes an upper portion having a lock recess formed therein for receiving the lock tongue of the lever.
The lower portion of the tension rod includes an outer thread formed thereon, and a fastener threaded to the outer thread of the tension rod and engageable with the rear portion of the arm.
Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings.